The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
With the development of communication technology, communication terminals are used in various applications, which include navigations, position trigger social networks, position based commercials and products and services search. Most of these services utilize technologies, such as GPS (Global Positioning System) or AGPS (Assisted GPS), to identify the current position of the communication terminal and hence the user using the communication terminal. The technologies that identify the current position provide a reasonable accuracy of the position of the user while the user is in the outdoor environments. However, the signals used to locate the user would be severely interfered and blocked when the communication terminals are held indoors, which may cause a failure to confirm the positions of communication terminals precisely. Further, other communication technologies could be used to obtain the current position of the communication terminal.
However, for indoor or outdoor environments surrounded by buildings, GPS usually fails to provide a precise positioning, because the satellite signal is weak. The buildings affect the satellite signal of the GPS. Moreover, communication terminals may receive fewer than three satellite signals when there are many buildings crowded around the communication terminal. In this case, GPS is unable to offer a favorable positioning signal. Therefore, if user is indoors or between many buildings, GPS would fail to provide the relevant information about the terminal position to determine a the terminals position or to accurately determine the terminals position.
Triangulation of Wi-Fi (Wireless Broadband) signals provides a competitive technology of indoor positioning. Wi-Fi signals are effective under normal circumstances, and the installations of new devices may not be required for receiving the signals. On the other hand, Wi-Fi signals can make positioning mistakes as a result of the Wi-Fi signals traveling through walls. Moreover, the Wi-Fi signal strength is a part of the iOS (formerly iPhone OS, the handheld operating system developed by the Apple Inc.) private API (Application Programming Interface), which prevent iPhones from using their Wi-Fi to determine the position of the iPhone. So, the effect is not ideal. Also Wi-Fi fails to perform location authentication of mobile device within the same region as the fixed device of the present invention.
To sum up, the present location authentication within the same region has inconvenience and defects. Thus, improvements may be desirable.